In an injection molding machine, when molten material is to be injected into a mold attached to a stationary platen as a part of a mold clamping mechanism, typically an injection mechanism is moved toward the mold clamping mechanism; a nozzle of a heating cylinder mounted on a leading end of the injection mechanism is brought into contact (also referred to as “nozzle touch”) with the mold attached to the stationary platen as a part of the mold clamping mechanism; and the molten material is injected into the mold while a pressure (also referred to as a “nozzle touch force”) is applied to the nozzle.
The injection molding machine therefore has a nozzle touch mechanism for applying the nozzle touch force to the stationary platen.
A known injection molding machine has a nozzle touch mechanism that includes a sliding section, mounted with an injection mechanism, for making the injection mechanism movable and a driving section for moving the injection mechanism along the sliding section. The injection molding machine further includes a connection mechanism having one end supported on a stationary platen and the other end supported on the driving section of the nozzle touch mechanism. The connection mechanism is supported on the stationary platen at least two points that are disposed at symmetrical positions relative to a central axis of a nozzle. The nozzle touch force is thereby transmitted to the nozzle touch mechanism via the connection mechanism. Such a configuration prevents the stationary platen and a mold attached to the stationary platen from being tilted by the nozzle touch force. (For example, see JP-2001-38764-A.)
However, the injection molding machine described in JP-2001-38764-A is based on the premise that the mold is attached to the stationary platen. In addition to this premise, the stationary platen and the mold attached to the stationary platen are prevented from being tilted due to the nozzle touch force. In the injection molding machine described in JP-2001-38764-A, the stationary platen tilted when the mold is attached to the stationary platen is not taken into consideration. Thus, mold opening and closing operation, injection operation, dwelling operation, and cooling operation may be performed in some cases while the stationary platen and the mold attached to the stationary platen are still tilted.
The inventors developed the injection molding machine that can prevent the stationary platen and the mold attached to the stationary platen from being tilted for a period of time during which the nozzle touch force is applied (refer to JP-2012-11767-A). The tilt (the bending moment) of the stationary platen occurring when the mold is attached to the stationary platen is also taken account of in this injection molding machine. The tilt of the stationary platen and the mold attached thereto is avoided for the period of time during which the nozzle touch force is applied.